The present invention relates to methods for remediating food and beverage products contaminated with taint compounds which introduce undesirable flavors or odors into those foods and beverages. In particular, the invention relates to wine and the contamination of wine with 2,4,6 Trichloroanisole (TCA) which is also known as “cork taint.” TCA imparts a moldy/musty odor to wine and is molecule produced by a metabolic reaction of mold organisms with chlorine and chlorinated compounds. TCA taint in wine is typically associated with cork, however, other media related with wine production and storage can also lead to TCA formation. While the human detection threshold for TCA is considered to be above 5 nanograms per liter (part per trillion) of wine it may be capable of suppressing the positive fruit aroma character in some wines at levels as low as two nanograms per liter. Damage to the wine industry worldwide from TCA taint is estimated to total $10 billion worldwide.
The food and beverage industry, especially wineries, need a cost effective and efficient method for preventing taint compounds from entering products during manufacturing, packaging, storage, and the distribution processes. A technology allowing end consumers to remediate foods and beverages immediately prior to consumption would also be beneficial. A number of solutions have been proposed to prevent products from becoming tainted and for the remediation of products already contaminated. These solutions have had limited acceptance principally due to the quantities of treatment material required, their costs, and their tendencies to change the flavor profiles of the products being protected or remediated. For example, technologies capable of removing TCA from contaminated products may also remove different desired compounds.
Zeolite technologies are among the tools applied to selectively remove molecules from various matrices. While there are numerous references regarding the adsorption of halogenated aromatics by zeolites, a literature search indicated there are no examples of zeolite adsorption of polychlorinated anisoles such as TCA.
Recently, Andersson et al. (J Appl. Polym. Sci. 95:583-595, 2005) placed a proprietary hydrophilic mixture of zeolites in low-density polyethylene films for use in food packaging. The zeolite was employed in this application to trap the degradation products of the polymer film preventing them from leaching into the food product. In the work of Andersson et al., the packaging film was the origin of the compounds that produce off-flavor in foods. The purpose of the zeolite in Anderson's technology was to retain these compounds in the film in order to minimize off-flavor effects. The ultimate goal of this work was to prevent the packaging material from influencing the aroma profile. A multitude of degradation compounds were targeted for adsorption instead of the focused targeting described in our novel approach.
Similarly, Trouilhet, U.S. Pat. No. 5,750,611 describes the use of molecular sieves to minimize the odors and flavors associated with thermoplastic films. Again, this technology focused on non-selectively retaining the odors and flavors that are created due to the polymer itself or breakdown products resulting from additives deliberately mixed into the polymer. These references do not describe a process in which the odors and flavors are selectively prevented from entering the food product but rather describe a technology in which a nondescript myriad of odor and flavor molecules are adsorbed.
Of interest to the present invention is a remedial treatment described in Swan, U.S. Pat. No. 6,610,342 which uses aliphatic synthetic polymers to remove off-flavors and odors from foods and beverages. This technology requires a comparatively large amount of synthetic polymer to remove a relatively small amount of taint. Swan's treatment calls for the use of roughly 150 grams of polymer to treat 1 liter of beverage. An example given for this technology describes the use of roughly 63 grams of an ultra-high molecular weight polyethylene (UHMWPE) to reduce TCA levels from 87.5 to 6.4 parts per trillion, in 0.75 liters of wine. The wine was filtered through a bed made up of the UHMWPE at a rate of 5 ml/min. The total filtration time for the 0.75 liters was consequently 2.5 hours. This translates to an average TCA removal rate of approximately 0.54 nanogram (ng) per minute and a capacity of 1.3 ng TCA removed per gram of treatment material. The novel technology described herein has taint removal capacities that are orders of magnitude larger than Swan's UHMWPE polymer. In addition, the presently described adsorbent technology removes these comparatively large taint amounts in seconds rather than in minutes or hours.
Another method used to remove taint from wine utilizes milk or the combination of milk and diary cream known as “half-and-half.” The application of this technique has been approved by regulatory authorities in the past at a usage rate of 2 liters of milk or half-and-half per 1000 liters of wine. This method is stated to be capable of removing TCA without significantly changing the phenolic profile of the wine but no quantitative information regarding the aroma profile was provided. Half-in-half is said to perform better at removing TCA due to its higher fat content. Milk use at this rate is approved by the federal government (27 CFR 24.246 Materials authorized for treatment of wine and juice.) for the fining of specific types of wine. A usage rate for taint removal of 10 liters of milk or half-in-half per 1000 liters of wine has been proposed.
The capacity, selectivity, and speed of half-and-half for TCA removal have not been specifically reported for these studies and the efficacy of this method is unclear. Nevertheless, the addition of milk products to wine and the subsequent removal might be relatively expensive. Moreover, the use of milk products could also raise questions regarding the acceptability for consumption by individuals with allergies to dairy products.
Although the wine industry has made strides in minimizing the potential for TCA contamination, the problem remains. Accordingly, there remains a need for methods allowing for the fast, selective, and economical removal of TCA in a manner which do not remove other desirable components or otherwise change the contaminated product's flavor and aroma profiles.